Among these datasets, DIV2K [1]} is the most widely used dataset for model training, which is a high-quality dataset that contains 800 training images, 100 validation images, and 100 test images. Flickr2k is a large extended dataset, which contains 2650 2K images from Flickr. RealSR [2]} is the first truly collected SISR dataset with paired LR and HR images. In addition to the listed datasets, some datasets widely used in other computer vision tasks are also used as supplementary training datasets for SISR, such as ImageNet [3]} and CelebA [4]}. In addition, combining multiple datasets (e.g., DF2K) for training to further improve the model performance has also been widely used.
